基于群路QPSK信号全数字化整体解调的大频差估计算法  

On Ensuring Acceptably Small Frequency-Offset in DigitizedDemodulation of Multi-Channel QPSK Signals

作　　者：周德锁[1] 王锋[1] 

机构地区：[1]西北工业大学电子工程系

出　　处：《西北工业大学学报》2002年第1期87-90,共4页Journal of Northwestern Polytechnical University

基　　金：国家自然科学基金(69872027)资助

摘　　要：主要是解决数字接收机中，对多路QPSK信号解调时所存在的较大载波频差的难题。采用理论研究分析和仿真验证相结合的方法，提出了一种将对大频差的直接估计转换成对一个已知序列的周期估计的新算法．该算法可以将实际解调中存在的用现有算法较难解决的大频差问题用一个较为简单的算法进行有效的估计和矫正，解决了数字化解调中的一个难题。研究认为，所提算法具有简单、计算量成小、统计特性好等特点，特别适用于多路QPSK信号的数字化解调。仿真结果表明该算法是可行的，目前已在实际系统中得到应用。Abstract: Digitized demodulation of multi-channel QPSK signals often can not proceed normally due to the occurrence of unacceptably large frequency-offset. We now present an algorithm for estimating large frequency-offset and rectifying it to make it acceptably small. Section 1 gives the mathematics underlying our algorithm. Section 2 discusses in much detail the estimation of large frequency-offset and the proposed rectification to make it acceptably small. We like to point out that eqs. (11) and (12) are particularly important. Simulation results, as given in Tables 1 and 2, show preliminarily that our algorithm is feasible. Moreover, our algorithm functioned smoothly when it was employed in an actual system for digitized demodulation of 32-channel FDMA/QPSK signals implemented on TMS320C6X.

关 键 词：大频差估计 频差矫正 多路QPSK信号解调 数字接收机 全数字化整体调解 数字通信系统 

分 类 号：TN851[电子电信—信息与通信工程] TN914.3